Transformer tank



' Sept. 28 ,.192 1,601,307

L. H. HILL TRANSFORMER TANK Original Filed August 50. 1923 INVENTOB Lela/7d If.

Patented Sept. 28, 1926.

UNITED STATES PATENT OFFICE.

LELAND H. HILL, OF WILKINSBURG,PENNSYLVANIA, ASSIGNOR'TO VJESTINGE IOUSE ELECTRIC & MANUFACTURING COMPANY, ACORBORZATION OF "PENNSYLVANIA.

TRANSFORMER TANK.

Applieation'flledAuguet30, 1923 Serial No. 660,116. Renewed February 18, 1926.

My invention relates to transformers, and it has particular relation to such transformers as embody oil for insulating the electrical apparatus from the tank or container.

My invention has, forone of its objects, to provide a liquid seal of simple construction for isolating the spaceabove the insulating oil from the atmosphere.

.A second object of my invention is to provide a liquid seal for a transformer, the structure of which is integral with that of the transformer tank.

In constructing a transformer in accordance with my invention, a series of-compartments are arrangedalong-the sides and .in the baseof the transformer tank. The horizontally-extending compartment in the base and one of the vertically-extendingcompartments contain a quantity of oil or liquid whereby they constitute a liquid seal. The other compartment contains deoxidizmg material for rendering inert the air or gas within the transformer.

In the accompanying drawing,

Figure 1 is a view, partially in elevation and partially in section, of a transformer constructed in accordance with my invention; and

Fig. 2 is a view of the transformer casing in transverse section taken along the line 11-11 of Fig. 1.

Referring to the drawing, a transformer 1 comprises a tank 2 that is partially filled with insulating oil indicated at 3. The tank is provided with a cover member 4 from which the terminals of the transformer windings are insulated by means of sultable bushings 5 and 6. The space 7 above the insulating oil is initially occupied byordinary air.

The tank 2 is provided with a series of communicating compartments 9, 10 and 11. The compartments 9 and 11 extend vertically along the sides of the transformer while the compartment 10 extends horizontally in the base of the tank.

The compartment 9, which communicates with-the space 7 by meansof an opening 13 in the wall of the tank, contains deQxid zing and dehydrating material indicated at 14 that is held within a container 1, 9f Woven material or perforated material, whereby air or gs may readily P3 8 The container 15 and the deoxidizing material are so arrangedas to divide the compartment 9 into two parts, one of which'communicatcs with the opening 13and the other of which communicates through an opening 17 with the compartment 10.

Theacompartment 10, which is relatively shallow but of substantially the same transverse cross-sectional area as that of the compartments 9 and 11, is provided with the opening 17 at its top and with an opening 18 near the bottom thereof for communication withathe' compartment 11.

The vertically-extending compartment 11 iseonnected tothe atmosphere by a suitably curved, downwardly-projecting pipe 19. The compartments 10 and 11 normally contain a sufficient quantity'of oil, indicated'at 20, or other suitable liquid, that is substantially equal in volume to that of the compartment 10 for-a purpose to be hereinafterdescribed.

lVhen the transformer and its associated partsare assembled, as shown in the drawing and described above, the air within the space 7 is gradually deoxidized by the deoxidizing material in the compartment 9. Ifthe operation has not been completed before the transformer is placed in operation, the removal/of oxygen therefrom is hastened by the breathing or exchange of air between the transformer tank and the atmosphere.

It may be assumed that the transformer is being placed in operation. It may be assumed further that the temperature of the transformer is increasing by reason of the heat losses in the windings of the apparatus. Theoilexpands and causes a corresponding increasein pressure of the air or gas in the space 7. This pressure is transmitted through the opening 13, compartment 9 and opening 17 to the oil 20 within the compartment 10.

Oil is accordingly forced from the compartment- 10 into the compartment 11 until the head of oil Within the latter compartment equals the pressure within the space 7.

In case the pressure rises to such degree that the level of the oil in the compartment 10 is below the upper portion of the opening 18, air or gas escapes throughout opening 18 and through the oil in the compartment 11 to the atmosphere, Upon the relief in pressure'caused by the escape of gas, oil will again from the compartment 11 into the.

com artment 10. These operations will be repeated upon each occurrence of the pressure increasing to the predet rmined value at which air may escape through the opening 18.

It will be noted that the pressure rcquirec to expel air or gas from the transformer is measured by the head of oil within the compartment 11 since the pressure caused thereby is transmitted through the opening; 18 to the oil within the compartment 10.

During normal operation of the trans tormer, the variations in pressure are comparatively slight and few or no exchanges of gas or air between the transformer and the atmosphere are necessary.

In case the temperature of the trans iorme falls for reason, such, for example, removing the load from the transformer, the volume of oil therein will diminish corre spondingly. The pressure within the space that of the decreases and is lower tha atmos ahere. Accordingly, oil flows from the compartment 11 to the compartment 10 in order to equalize the pressures therein. Then the level of the oil in the Compartment 11 is below the opening 18, air flows from the compartment 11 to the compart ment 10 and through the opening 17 and compartment 9, including the deoxidizing' material to the space 7.

The air entering the transformer in the manner just described is completely decridized and dehydrated by the material l t. substantially pure nitrogen entering the space T. Sullicient oil flows from the compartment 10 to the compartment 11 to equalize the pressures after the admission of air. This proc is repeated in case the fall. in temperature continues.

It will be noted that the ditierence in pressure between the interior of the tank and the atmosphere before air is admitted to the tank is that measured by the head of oil w'thin the compartment 10. It will be noted further that this pressure is materially less than that required before gas may be expelled from the tank. The relation of the respective pressures may be arranged as desired by suitably proportionina the horizontal cross-sectional areas of the conr partments 10 and 11 in order to determine the rates at which the levels therein vary during an exchange of oil therebetween.

The provision of a liquid seal of the character described above operates automaticalhto control the pressures at which air or gas may be expelled from, or admitted into. a transt'orn'ier tank. The limiting of exchanges of air or breathing to the occurrence of predetermined difierences in pressure materially reduces the breathing during; normal operation of the transformer and serves to economize in the consumption of deoxidizing material. The arrangement of the coni partments along the sides and in the base of the tank economizcs space and provides a simple and convenient construction.

While I have shown my invention as applied to transformers, it is equally applicable to circuit breakers and electrical apparatus oi a similar nature. Various modifications will occur to those skilled in the art to which my invention appertains and it is understood that my invention is not limited except as indicated by the appended claims I claim as my invention:

1. The combination with a tank, of a liquid seal therefor comprising two communicating compartments and a quantity of liquid therein, saidcompartments being so disposed and arraiigerjl that the level of liquid therein varies at dili'erent rates upon an hange of lie id therebetween.

The comb ration with a tank oi a liql seal therefor comprising' two communi eating compartments of unequal horizontal cross-sectional area and a quantity o't liquid therein whereby said seal opens atdifferent pressures in the respective directions.

3. The combination with a tank and a rel atively shallow compartment having an upper opening comn'iunicating with said tank, ot a relatively deep compartment connected to a lower opening in the shallow compartment and a quantity of liquid in said compartments whereby air or gas t 'averses said compartments at predetermined pressures in the respective directions.

-l-. The comliiination with a tank and a compartment, of means for supplying liquid to said compartment, said compartment having an upper opening communicating with the upper portion of said tank and a lower opening connected to the liquid-supplying means whereby said compartment constitutes a liquid seal that permits gas to escape from said tank at a relatively high pressure and permits air or gas to be admitted to said tank at a relatively low pressure.

The coml'iination with a tank partially filled with insulating fluid, of a compartment communicating with the space above said fluid, said compmtment having open-- lugs at different levels and means for sup plying liquid to one oi said openings whereby said compartment constitutes a liquid seal for permitting air or gas to traverse said compartment at pressures applied thereto which dill'er in value according" to their direction.

(3. The combination 'ith a tank, of means for controlling the connection of said tank to the atmosphere, said means comprising a horizontally-extending compartment connected at its upper portion to said tank, a verticallyextending compartmentconnected to the lower portion of the first-named compertinent, and a quantity of liquid in said compartments. whereby air or gas 1s ex pelled from said tank against the head of liquid in the vertically-extending compartment and is admitted to said tank against the head of the liquid in the horizontallyextending compartment.

7. The con'ibination with a tank, of a liquid seal therefor comprising a con'iparti'nent extending beneath the base of said tank a second compartment extending along the side of said tank and communicating with the other compartment and a quantity of liquid in said compartments.

8. The combination with a tank, of a liquid seal therefor comprising a compartment extending beneath the base of said tank, a second compartment extending along the side of said tank and communicating with the other compartment and a quantity of liquid in said compartments, and deoxidizing apparatus connected between said tank and the first-named compartment.

9. The combination with a tank partially filled with insulating oil and deoxidizing apparatus communicating with the space above the oil, of a liquid seal for controlling the connection of said apparatus to the atmosphere, said seal comprising communicating compartments respectively in the base and on the side of the tank.

10. The combination with a tank partially filled with insulating oil, oil a series of coin partments along the sides and base of said tank, deoxidizing means in one compartment which coinn'mnicates with the space above the oil, an intern'iediate compartment communicating at its upper portion to said one compartment and at its lower portion to a third compartment, said third compartment con'm'iunicating with the atmosphere and a quantity of liquid in the intermediate and the third con'ipartments.

In testimony whereof, I have hereunto subscribed my name this 23rd day of August 1923.

LELAND H. HILL. 

